Trailer trucks are conventionally provided with air brakes on the trailer which require connection of air hoses from a pump on the truck cab extending to the brakes at the wheels of the trailer. Also, the electric lamps on the trailer are supplied through an electric cable from the battery in the cab. When the cab is disconnected from the trailer, the air hoses and the electric cable are disconnected from the trailer. For this purpose, each air hose extending from the cab terminates in a coupling unit, known as a gladhand, which mates with a fixed coupling unit, also a gladhand, on the trailer; the electric cable from the cab terminates in a plug which mates with a receptacle fixed to the trailer. When the cab is operated without the trailer, it is necessary to retain the air hose couplings and the electric plug on the rear of the cab so they will not be damaged and with an air tight seal on the air hose coupling.
Heretofore, it has been a common practice to mount a socket member on the rear of the cab for retaining the electric plug when it is disconnected from the trailer. The air hose glandhands present a more difficult problem; not only must the gladhand be held in place on the cab but also it must be sealed against the high pressure in the hose. The standard gladhand is adapted to serve as a quick disconnect coupling for the air brake hoses which carry high air pressure. For this pupose, the standard gladhand is constructed with a palm portion defining a circular air passage surrounded by an annular seal of rubber or other elastomeric material. It has an arcuate finger portion with a first cam surface on the backside and an arcuate heel portion with a second cam surface facing the palm portion and offset therefrom. The gladhand is adapted to be coupled with a complementary gladhand of the same construction by placing them plam-to-palm and rotating them in the plane of the palm so that the cam surface in the finger portion of one engages the cam surface in the heel portion of the other and vice versa. The rotational motion of the engaging cam surfaces causes the palm portions to be pressed tightly together with attendant compression of the elastomeric seals to produce an air tight coupling. Because of the need for maintaining an air tight seal during all operating conditions of the truck, the gladhands are designed so that a high value of torque is required for connecting and disconnecting a pair of gladhands. The air hose fitting is attached at the heel of the gladhand and serves as a handle for the operator in rotating the gladhand for connection and disconnection.
In the prior art, it is common practice to provide gladhand keepers on the rear of truck cabs. One known form of gladhand keeper is made of heavy gauge sheet steel in a one-piece construction. It comprises a generally flat body having a partially-spherical protrusion stamped therein to coact with the annular seal on the gladhand to provide an air tight connection. The body is provided with a pair of legs, each extending perpendicularly from the body and terminating in a foot which is adapted to be bolted onto the panel of the truck cab. A first tongue portion, having an inverted J-shape in cross-section, extends upwardly from the flat body to receive the finger portion of the gladhand. A second tongue portion extends downwardly from the flat body and is offset inwardly therefrom to be engaged by the cam surface of the heel portion of the gladhand. In this prior art, the gladhand is oriented relative to the keeper so that the palm of the gladhand is face-to-face with the flat body of the keeper. This requires the operator to rotate the gladhand in a plane parallel to the rear panel of the truck cab when the gladhand is connected and disconnected from the keeper.
The prior art gladhand keepers, such as that described above, are difficult and sometimes dangerous for the truck driver to use. The keeper for the pair of gladhands and the electric plug are separate and sometimes spaced from each other at relatively inaccessible locations. The gladhands require a forceful rotation in a plane parallel to the rear panel of the cab. The engagement of the rubber seal with the metal keeper results in large friction loading and requires a larger force to be exerted. Since a large force is required to connect the gladhand to the keeper and since the keeper is frequently installed in a hard-to-reach location, the driver often climbs onto the rear of the cab to connect or disconnect the gladhand. The effort of rotating the gladhand in the plane of the cab panel, especially under adverse weather conditions or the like, might result in loss of footing and injurious fall.
A general object of this invention is to provide a keeper for a pair of gladhands and an electric plug which overcomes the disadvantages of the prior art.